The invention relates to an apparatus for testing flow noise of a motor vehicle and, in particular, to an apparatus having a blast nozzle device with at least one blast nozzle and a transport device. The blast nozzle device is designed for the targeted impingement of the outer skin of the motor vehicle by air flow, and the transport device is designed in such a way that the blast nozzle device and the motor vehicle may be moved relative to one another. The invention further relates to a corresponding method for testing flow noise of a motor vehicle.
German Utility Model DE 203 20 885 U1 describes an apparatus of the afore-mentioned type, which is designed in the manner of a test bench, whereby the blast nozzle device which includes at least one blast nozzle may be routed past regions of the outer skin of the bodywork of a passenger vehicle by way of a transport device. A disadvantage of the known apparatus is that the test results are not based on objective measurements, but rather on the subjective impression of the tester, which results in an unavoidable variation. The measurement process for the known apparatus is not reproducible with sufficient reliability.
There is therefore needed an apparatus and a method for testing flow noise of a motor vehicle, in particular a passenger vehicle, wherein the disadvantages of the prior art are avoided and the measurement of flow noise produced by the impingement of the outer skin of the motor vehicle by air flow may be carried out in a particularly precise, reliable, and objective manner.
According to the invention, an apparatus is provided for testing flow noise of a motor vehicle, the apparatus comprising a blast nozzle device having at least one blast nozzle and a transport device. The blast nozzle device is designed for the targeted impingement of the outer skin of the motor vehicle by air flow, and the transport device is designed in such a way that the blast nozzle device and the motor vehicle may be moved relative to one another. A microphone array is provided, which is designed for positioning in the interior of the motor vehicle and for measurement of the flow noise in the interior of the motor vehicle.
Further, according to the invention, a method is provided for testing flow noise of a motor vehicle, wherein a blast nozzle device and the motor vehicle are moved relative to one another. The outer skin of the motor vehicle is impinged on in a targeted manner by air flow by use of the blast nozzle device. The flow noise in the interior of the motor vehicle generated by the air flow is measured by use of a microphone array. Advantageous refinements of the invention are described and claimed herein.
The primary advantages achieved by the invention are that an objective localization of the source of errors that is independent of the subjective impression of an evaluator is made possible for wind noise, which may be perceived in the interior of the motor vehicle. The testing is carried out with very high reliability and measurement accuracy.
The reliability of localization of the source of noise in the interior of the motor vehicle may be further increased by the use of a microphone array designed as a spherical array. In this manner, in particular interference effects in the relevant frequency range above 1000 Hz may be avoided.
The microphone array may advantageously be coupled to an optical recording device. In this manner, it is possible to establish an extremely accurate and reliable relationship between noise sources and the structure of the interior of the motor vehicle.
A connecting device may advantageously be provided, which is preferably connected to the microphone array, and by which the microphone array may be positioned in the motor vehicle such that a defined position of the microphone array relative to one or more elements in the interior of the motor vehicle is ensured. Particularly reliable and reproducible test results may be obtained in this manner.
The orientation of the blast nozzles of the blast nozzle device may advantageously be adapted to the outer contour of the motor vehicle to be tested. This adaptation may be made continuously during the test procedure. In this manner, even motor vehicles with very different outer contours may be tested in direct succession, if necessary, without the need for complicated repositioning or resetting activities, for example. In this regard, it may be practical to measure the outer contour of the motor vehicle, for example by use of one or more optical sensor devices. To adapt the orientation of the blast nozzles to the outer contour of the motor vehicle, one or more blast nozzles of the blast nozzle device may be pivotable so as to be adjustable in the vertical, longitudinal, and/or transverse directions.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.